i am designing a radio modem which will take input from pc rs232 and output tones in audio freq which will be sent over a simples radio.
i am using an fsk modem and atmel 89c52 to control it.

i need help in c source code for serial comn at microcontroller level. i shall be using a ls74125(tristate buffer) for ser port multiplexing. i shall be receiving rs232 data by microcontroller ser port and sending it to modem chip for further modulation.

i need a circuit diag and c source code.

pls help

 

Hello,

I can help you .can you send me which chip you are using for the fsk modem regs

venkat